I’m making badges and I want them to be magnetic. What I’d like to do, however, is to embed a thin strip of metal into my wood. This metal would be the same as… you ever see the thin metal strips that come with magnetic cellphone mounts? The metal’s supposed to be inserted into your battery cover. Ya know what I’m talkin’ about? Basically, I want that. It’s so thin you can cut it with scissors, but magnets stick solidly to them. I’m finding it difficult to search for such a thing because of the generic wording I’m coming up with.

I got a badge at a conference recently that used these - very classy! The ‘snap’ as the magnets connect to the metal strip in the badge is very satisfying, and no holes in your suit. Looks a lot nicer than a lanyard, too.

Any time a conductor moves through a magnetic field, or a magnetic field moves through a conductor, it induces current flow in the conductor. In a flat piece of metal, this causes the current to flow in a circle. The current flowing is impeded by the resistance of the metal, causing heat.

Panasonic has sold “All Metal” induction cooktops in Japan for seven or eight years now. They simply have to drive the magnetic field at a higher frequency. It’s less efficient than ferrous pans (around 75% for aluminum or copper, vs. 90% for steel) but it works.

Besides being less efficient, other downsides include the cost (they’re much more expensive, and inductive cooktops are already more expensive than other kinds of stoves) as well as a tendency for lightweight pans to levitate(!!!) when used on it, which can be problematic as it makes it much easier to knock them off the stove.

Thanks! I did include the ‘for nearly all models of induction cooktops’, but should have also shaded my comments below that to reflect that. But I would think the efficiency would be much less for Al or Cu, since on my induction they don’t heat up at all. Or maybe I never did the experiment right due to bias. Or maybe the sensor that checks for use of a proper pan kicks in. Hum, guess what I’m going to try out on my 3.5 KW stovetop later today.